Since it doesn't seem like bit-pay has a support thread I am wondering if I am missing the obvious or does bit-pay not ever provide the payment address in the API call?https://bit-pay.com/downloads/bitpayApi.pdf
Create an invoice return values
id - The unique id of the invoice.
url - An https URL where the invoice can be viewed.
posData - A data field provided by the merchant and designed to be used by the merchant to correlate the invoice with an order or other object in their system.
status - The current invoice status. The possible states are described earlier in this document.
btcPrice - The amount of bitcoins being requested for payment of this invoice (same as the price if the merchant set the price in BTC).
price - The price set by the merchant (in terms of the provided currency).
currency - The 3 letter currency code in which the invoice was priced.
invoiceTime - The time the invoice was created in milliseconds since midnight January 1, 1970.
expirationTime - The time at which the invoice expires and no further payment will be accepted (in milliseconds since midnight January 1, 1970). Currently, all invoices are valid for 15 minutes.
currentTime - The current time on the Bit-Pay.com system (by subtracting the current time from the expiration time, the amount of time remaining for payment can be determined)
Hmm the obvious thing missing is the actual payment address.
Now I know bit-pay does provide a url to a "fancy" invoice screen but I would prefer tighter integration. My site, my layout, showing the payment address the user needs to pay.
bit-pay provides everything else that is necessary including call back address to provide updates (so user's payment screen can "auto update". Everything except the actual payment address.
paysius is an alternative but their current implementation allows a fatal replay attack. paysius operator if you have a presence PM me (hint: messages need to be unique).